An air strike by the US-led coalition countering the Islamic State of Iraq and the Levant (ISIL) group may have led to the death of Iraqi soldiers, the US military said in a statement.
After acting on information from Iraqi security forces on the ground near Fallujah, coalition forces conducted several air strikes against ISIL and "initial reports indicate the possibility one of the strikes resulted in the death of Iraqi soldiers," the statement said.
"We will conduct a thorough investigation to determine the facts," it said, adding: "To the best of our knowledge, there have been no previous incidents of friendly fire in Iraq involving the Coalition during the course of Operation Inherent Resolve."
ISIL made most of its gains in Iraq in the summer of 2014 during a rapid offensive that resulted in the government losing most of Anbar.
Fallujah and much of Anbar, including its capital Ramadi, are made up mostly of Sunni Arabs.
Iraq's defence minister predicted on Saturday that security forces backed by US-led coalition air strikes would retake full control of the city of Ramadi by the end of the year.
"I met with the Joint Operations Command and they confirmed to me that we will regain all of the city of Ramadi by the end of this month," Khaled al-Obeidi, the defence minister, told reporters in Baghdad.
Iraq's attempts to regain territories from ISIL have been backed by a number of countries including Iran, the US, and several European states.
Source: Al Jazeera and agencies